This invention pertains to a method and apparatus for converting conventional bottle crowning machinery for the application of lightweight metal tear off closures.
In U.S. Pat. No. 3,470,667 to C. David et al dated Oct. 7, 1969, there is disclosed a bottle crowning machine comprising a rotary crowner turret within which is reciprocally mounted a series of crowner plunger assemblies. This patent teaches the concept of interchangeably attaching either a conventional crown applying mechanism or a cap crimping head to the lower end of each plunger assembly whereby a conventional bottle crowning machine can be alternately employed for the application of crowns and lightweight metal tear off closures. My own U.S. Pat. No. 3,524,294, dated Aug. 18, 1970, discloses a somewhat different arrangement also for converting conventional crowning machinery for the interchangeable application of crowns and tear off closures. In that instance the conversion was accomplished by only partially disassembling the crowner mechanism, i.e., removing the crowner platform and throat subassembly and substituting a tear off closure crimping head in its place. This arrangement offered the advantage of utilizing the remaining crowner mechanism to actuate the crimping head and thus greatly simplified the conversion of certain machines.
The problem left unresolved by the two above mentioned patents concerns the ready conversion of certain crowning machines which for one reason or another do not supply the necesary mechanical action and safeguards for proper actuation of the tear off closure applying head. For example, a predetermined amount of vertical loading must be incorporated in the downward movement of the crowner plunger assembly to permit adaption of the crimping head in place of the conventional crowner mechanism. This vertical loading must become effective during the cap applying stroke in such a fashion as to compensate for normal bottle height variations and thus protect against damage to either the bottle or the crimping head. In those existing crowning machines which do not adequately provide for this type of compensation, the suitability for conversion to the application of tear off closures has, heretofore, remained questionable due to the rather extensive mechanical alterations required in the crowner plunger assembly.